birdwatcher

noun3

1. •
   A person who observes or identifies wild birds in their natural environment.

   • Alec Warner was gazing like a bird-watcher at Charmian, who plucked at the rug round her knees, waiting to tell her own story. — 1959
2. •
   (slang) A person who enjoys watching rocket launches.

   • In fact, on this night, the birdwatching is over for everyone, for the firing is cancelled. Nobody notifies birdwatchers officially, of course, so the exodus is scattered and gradual. — 1957
3. •
   (slang, humorous) A person, especially a male, who delights in watching women.